This is an area of interest for me. I have worked with Stainless materials of different grades ranging from the cheap stuff to the exotic stuff and gleaned some knowledge from it. I would say the average stainless barrel material has a higher tensile strength at average temperatures than say a carbon steel barrel. Chrome depends on the quality of the chrome coating and even then it has it's thresholds like anything. Cutting stainless requires tools running at slower speeds, often times sulfer based cutting fluids, versus carbon steel. Despite this, carbon steel is harder to machine due to increased density on average. Chrome lined is just a layer or series of layers, so they are prone to failure if they are not applied properly. If done properly they can be extremely precise. That said stainless gets hot and it tends to become more malleable instead of tearing or shearing. As long as your rate of fire and heat is kept within reasonable levels, you may see long lifespans with 416 type grades of stainless. If you look at HK's "ordinance steel" which is basically a well processed CHF 416R from what I have researched, it makes sense the properly manufactured HK barrels can get 20,000 rounds down the pipe before losing more than 1-2 MOA accuracy. CHF does not do much for longevity, other than possibly makes the barrels molecular structure more uniform. What CHF does do is increases consistency, and that is always a good thing for accuracy. Something I buy into is cryo treatments and stainless is prone to temperature flux aberrations, so I would go with cryo if it's a cost effective option. It's not a pricey and exotic as it used to be.
Continue doing what you're doing until the accuracy drops off and pull the barrel and inspect it inside and out: and replace it. DPMS is a really good company, and they may be interested in hearing about it, if you track your round count and can explain how it was used. But good Stainless is tough as hell: it's why Barsto uses it, due to its tensile strength. If you were an arctic shooter, some stainless does not like temps below -60 which is a reality in the arctic, so carbon steel barrels are the way to go up there. You probably wont have problems with stainless, but you'll be shearing more material off in the extreme cold per shot at critters etc. Around -70 you might experience a barrel failure with stainless, but who hunts at -70? lol
Shoot it and enjoy. 1/2 MOA is good by my standards, I have a tough time finding factory loads that shoot 1/2 MOA not being able to reload. I would be interested to see how many rounds you get before it drops below 1MOA? Cool stuff. In the military we used Colt's chrome lined barrels for the most part, and when you're training with high volume fire, or in an actual fire fight the rate of fire can really tear up the bore of a barrel. Most infantry rifle's would end up in the scrap heap due to external wear issues, and the barrel's bore would be serviceable: because the guns would get beat on but shot less often. Working with special forces, the high volume fire in training and tendency to get into more fire fights due to a high op tempo would destroy the insides of the barrels. The same Colt barrels might last 15-20,000 rounds if they were range toys.
Hope this helps.
